http://www.anandtech.com/video/showdoc.aspx?i=2656&p=10
There's a sweet spot in price range with regards to performance. A pretty powerful ATI chip based X800 GTO video card can be had for 150-160$ on sale. That will get you 12 pixel pipelines and plenty of framerate on most games. For extremely high demanding you may need more power to run full anti-aliasing at high framerates such as when playing DOOM3 maxxed all out. But SH3 would play excellent of the X800 GTO.
For 200-225$ on sale. you could pick up a 16 pixel pipeline video card that could do more framerate in DOOM3. But for SH3 you'd not need that extra power.
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My system's framerate studders too using IMPROVED UBOAT 1.02. But i think we can adjust DOWN some of the particles and texture quality to compensate. I like the true sight distance so i can't ever go back to 8 miles. And if you stay in the scope view there's no framerate hit.
I've been too busy to play much but had some time now to take it on again using IUB 1.02. Last time i played i had time to go on two patrols and saw my first light cruiser far off. COOL!! Never actually saw a convoy yet. heeheehe. Though i prefer to hunt for a Task Force and a Carrier or Battleship.
On a good video card these ships will sure look neat no doubt. Nothing like the older subsims that's for sure. I've just seen the light cruisers thus far and am quite impressed with the power they seem to portray well in this game.
I'd like to see some battle between Task Forces someday. Is that a possible thing in the dynamic of the game i wonder?? I understand the Bismark is let loose in the game. Hopefully sometime in the Campaign mode as well as on Mission mode...